The present invention relates to completion systems for subsea oil and gas wells. More specifically, the invention relates to a universal interface system for the connections between the various components of the completion system and the tools which are used during installation and testing of the completion system.
Typical subsea completion systems comprise a number of permanently installed components, such as a wellhead, a tubing hanger, a tree, a tree cap, and a flowline jumper. Such systems usually also comprise a number of tools which are used temporarily during installation and testing of the completion system. These tools may include a lower riser package (“LRP”), an emergency disconnect package (“EDP”), a blowout preventor (“BOP”), and a tubing hanger running tool (“THRT”). During installation, testing, and production, these components and tools are stacked atop and connected to each other in a particular configuration.
Typically, the upper end of each of the wellhead, the tree, the EDP and the LRP comprises a hub having a specific external locking profile. In addition, the lower end of each of the tree, the EDP, the LRP, the flowline jumper and the BOP are normally equipped with a hydraulic connector for selectively engaging the external locking profile of another particular component. Furthermore, the upper end of the wellhead may include an internal profile in which the tubing hanger is landed. Moreover, in some systems the tree may include an internal profile which is adapted to receive the tree cap.
During the assembly, testing, and production phases of most common subsea systems, the various components are stacked in a particular order, such that each lower connector portion engages the upper hub portion of another particular component. Since each hub/connector interface can be designed independently, each interface is typically optimized for size, strength, and weight. Thus, the various hubs are often incompatible with all but the one connector they are specifically designed to mate with. The design of the tubing hanger/wellhead interface and the tree/tree cap interface are usually similarly customized. The result of this design philosophy is an inherent inflexibility in the installation and test procedures.